In his 38 years at NBC News, Robert Bazell has been at the forefront of NBC’s health and science reporting: from his coverage of AIDS to the earthquake in Haiti. NBC’s Natalie Morales reports.

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>>>we're saying so long to a beloved colleague tonight.
robert bazell
, chief science correspondent for almost four decades. he is beginning a new chapter in his career. in his 38 years with nbc news,
robert bazell
on the front lines and on the forefront of
science and health
reporting.

>>others get an infection.

>> reporter: in the early
1980s
, the first journalist to report on a new illness, even before it was called aids.

>> reporter: the scientist say this probably means they are dealing with a new deadly sexuly trancemismitted disease.

>>he chronicled the start of the
shuttle program
and helped guide us through the challenging day when the "challenger" exploded in 198 6. and talked about bird flew and whether it would spread worldwi worldwide.

>>research solves a great mystery in biology.

>> reporter: in iraq, he brought home the heavy toll of the conflict.

>>soldiers and marines rushed in.

>> reporter: and documented the suffering after the earthquake in haiti. helping us understand the world took him to some of the most fascinating places on earth.

>> reporter: the steam vents throughout the country are caused because water seeps into the earth and hit molten rock right beneath the surface.

>> reporter: he set a standard for
science journalism
. and bob has been much more than a colleague to many of us here at nbc news. a friend and never hesitated to lend a hand when health became personal. later this summer, bob will join the faculty of
yale university
. in the department of molecular, cellular and developmental biolo biology. we wish bob and his family all